package org.apache.torque.om;/* * Copyright 2001-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License") * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *     http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *//** * This class can be used as an ObjectKey to uniquely identify an * object within an application where the id  consists * of a single entity such a GUID or the value of a db row's primary key. * * @author <a href="mailto:jmcnally@apache.org">John McNally</a> * @version $Id: StringKey.java,v 1.9 2005/01/31 19:43:56 tfischer Exp $ */public class StringKey extends SimpleKey{    /**     * Creates an SimpleKey whose internal representation will be     * set later, through a set method     */    public StringKey()    {    }    /**     * Creates a StringKey whose internal representation is a String     *     * @param key the key value     */    public StringKey(String key)    {        this.key = key;    }    /**     * Creates a StringKey that is equivalent to key.     *     * @param key the key value     */    public StringKey(StringKey key)    {        if (key != null)        {            this.key = key.getValue();        }        else        {            this.key = null;        }    }    /**     * Sets the internal representation to a String     *     * @param key the key value     */    public void setValue(String key)    {        this.key = key;    }    /**     * Sets the internal representation to the same object used by key.     *     * @param key the key value     */    public void setValue(StringKey key)    {        if (key != null)        {            this.key = key.getValue();        }        else        {            this.key = null;        }    }    /**     * Access the underlying String object.     *     * @return a <code>String</code> value     */    public String getString()    {        return (String) key;    }    /**     * keyObj is equal to this StringKey if keyObj is a StringKey or String     * that contains the same information this key contains.  Two ObjectKeys     * that both contain null values are not considered equal.     *     * @param keyObj the comparison value     * @return whether the two objects are equal     */    public boolean equals(Object keyObj)    {        boolean isEqual = false;        if (key != null)        {            if (keyObj instanceof String)            {                isEqual = keyObj.equals(key);            }            // check against a StringKey. Two keys are equal, if their            // internal keys equivalent.            else if (keyObj instanceof StringKey)            {                Object obj = ((StringKey) keyObj).getValue();                isEqual =  key.equals(obj);            }        }        return isEqual;    }    /**     * get a String representation     *     * @return a String representation of an empty String if the value is null     */    public String toString()    {        if (key != null)        {            return (String) key;        }        return "";    }}